ROLE OF KUPFFER CELL-DERIVED REACTIVE OXYGEN INTERMEDIATES IN ALCOHOLIC LIVER-DISEASE IN RATS IN-VIVO

The pathophysiology of alcoholic liver disease (ALD) remains largely u nknown. In this work, we have developed an experimental rat model to e lucidate the mechanism of liver injury, including ALD, in which Kupffe r cell-derived reactive oxygen intermediates (ROIs) might be involved. Groups of male Wistar rats were pair-fed on a liquid high-fat diet co ntaining ethanol (36% of total calories) or isocaloric carbohydrate wi th or without dietary carbonyl iron (0.5% w/v) for 3 weeks. In this ra t model, we investigated Kupffer cell-derived ROI generation, which af fected hepatocellular injury and hepatic fibrosis in ALD. The producti on of ROIs in Kupffer cells isolated from the iron-fed, the ethanol-fe d, and the ethanol plus iron-fed rats were significantly increased, co mpared with that in Kupffer cells isolated from control rats (iron > e thanol + iron > ethanol >> control). However, hepatic vitamin E conten t in the ethanol plus iron-fed rats was decreased rather than that in the iron-fed rats. Then, lipid peroxidation of isolated microsomes was assessed as malondialdehyde equivalents determined by thiobarbituric acid assay. Compared with controls, the malondialdehyde equivalents we re elevated in experimental groups (ethanol + iron > ethanol > iron > control). Serum ALT levels were greatly elevated in rats fed a diet co ntaining both ethanol and iron (ethanol + iron > iron > ethanol > cont rol). Hepatic content of hydroxyproline was significantly increased in ethanol plus iron-fed rats, compared with rats other than the ethanol plus iron-fed group (ethanol + iron > iron > ethanol > control). Thes e results suggested that the enhanced Kupffer cell-derived ROI generat ion could itself contribute to the increased susceptibility to lipid p eroxidation, which might cause hepatocellular injury and lead to hepat ic fibrosis in ALD.